Bulletin of Chemical Reaction Engineering Catalysis, 10 1, 2015, 55
Copyright © 2015, BCREC, ISSN 1978-2993 increasing concentration of the catalyst was not
followed by a significant decrease in the amount of coke.
3.3. Effect of Reaction Time
Reaction time reflects the interaction be- tween reactants and reactant-catalyst in the
reaction system. The reaction time contributed mainly to the liquid yield was increased at 450
o
C until 78. Figure 4 shows the concentra- tions of RSO, diesel, kerosene, gasoline, gas
and coke against the reaction time. Generally, it can be observed that the increase in reaction
time resulted in the increasing concentrations of liquid products at catalyst concentration 0.5
wt. and reaction temperature 450
o
C with the highest gasoline concentration. This is because
the longer the reaction time, the longer the in- teraction, and the greater probability for reac-
tion. In these conditions, gasoline provided a high selectivity towards liquid product.
Gas product of lighter fractions as the conse- quences of advanced reaction seems occur. It
can be observed from the decrease in the con- centration of the gas product of light fractions
with increasing reaction time, the possible re- action
is the
polymerization reaction
incorporation of light fractions to heavier frac- tions and isomerization [16]. The effect of reac-
tion time on the product distribution indicates that temperature was also a main factor affect-
ing the conversion of long-chain hydrocarbon to middle-chain
hydrocarbon, and
continued cracking led to middle hydrocarbon goes to gas
fraction [19], low-chain hydrocarbon and coke by increasing the reaction time.
3.4. Effect of Catalyst
The catalyst can accelerate the rate of reac- tion that leads to more dominant products in
the equilibrium by lowering the activation energy. But the decline in activation energy
should be significant enough to accommodate an increase in the rate of reaction, or be accom-
panied by a very significant increase in fre- quency factor. If the decrease in activation
energy is not significant without a significant increase in frequency factor, the reaction rate
will decrease. If the research of liquid fuel de- velopment based on natural oil is seriously
engaged, the process with high efficiency and does not require a big expense need to be con-
sidered.
Figure 5 shows that the yield of the catalytic cracking at temperatures of 450
o
C for varia- tion of catalyst concentrations and reaction
times. The catalytic cracking products can be found in the form of liquid fuel, gas, and coke
products. The catalytic process for differences in reaction time of 30, 60, and 90 minutes can
be seen clearly that the longer the product of liquid fuel, the reaction process of the higher
product yields, especially a reaction time of 90 minutes to reach 78 yield. The use of a cata-
lytic amount ranges from without catalyst up to 2.0 wt. of liquid fuel is seen that the optimum
concentration of catalyst1.0 wt. that the reac- tion time of 30 minutes with a yield of 61.
This is in contrast that liquid fuel products with the reaction time of 60 minutes and 90
minutes using 0.5 wt. catalyst can achieve the highest yield of 72 and 78, respectively.
The highest yield of liquid fuels in the catalytic
Figure 4. Variation of reaction time of catalytic cracking at 450
o
C using 0.5 catalyst
Figure 5. Concentrations of catalytic cracking products at reaction temperature 450
o
C for dif- ferent catalyst concentrations and reaction times
Bulletin of Chemical Reaction Engineering Catalysis, 10 1, 2015, 56
Copyright © 2015, BCREC, ISSN 1978-2993
Table 3. Gaseous, liquid, and solid product of catalytic cracking of rubber seed oil
T
o
C
t
min Catalyst
wt. Xp
wt. LP
wt.
C
gasoline wt.
C
kerosene wt.
C
diesel wt.
C
gas wt.
C
coke wt.
350 30
0.0 11.6
5.3 3.2
1.5 0.5
0.4 0.5
350 350
350 350
350 350
350 350
350 350
350 400
400 400
400 400
400 400
400 400
400 400
400 450
450 450
450 450
450 450
450 450
450 450
450 30
30 30
60 60
60 60
90 90
90 90
30 30
30 30
60 60
60 60
90 90
90 90
30 30
30 30
60 60
60 60
90 90
90 90
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 0.0
0.5 1.0
2.0 14.8
45.8 34.6
17.9 35.7
51.0 67.1
34.4 65.8
56.7 74.7
68.0 82.7
65.8 58.8
46.5 65.7
69.0 74.0
49.5 78.7
78.0 82.9
54.1 71.7
89.1 77.3
65.7 97.0
91.7 94.7
74.6 96.6
97.9 97.9
11.9 37.4
26.6 15.4
24.7 43.1
53.6 30.4
52.1 46.7
53.5 55.2
67.7 53.2
45.6 39.5
52.0 60.1
58.6 43.6
59.4 58.7
67.3 39.2
47.7 61.1
50.2 51.5
69.6 71.6
72.0 62.4
78.0 71.2
78.0 7.3
19.8 9.4
8.3 13.6
22.9 22.3
20.4 35.0
25.9 29.4
30.5 40.1
31.2 25.6
24.9 31.5
35.2 33.7
27.4 35.7
34.0 37.8
24.5 30.6
42.3 33.7
34.9 46.4
44.4 44.6
39.5 48.3
43.8 45.3
3.9 8.2
10.5 2.8
4.0 9.5
9.5 8.4
13.9 10.8
17.4 14.5
20.8 13.0
13.9 10.6
13.0 15.1
16.3 14.1
18.3 15.8
22.3 12.4
14.8 17.2
14.6 16.0
20.3 21.4
23.5 20.4
25.9 22.7
24.6 0.7
9.4 6.6
4.3 7.1
10.7 21.8
1.5 3.2
10.0 6.7
3.5 6.8
9.0 6.1
4.0 7.4
9.7 8.7
2.1 5.4
8.9 7.2
2.2 2.2
1.7 1.9
0.6 2.0
5.8 3.8
2.4 3.7
4.7 8.3
1.1 2.9
2.5 0.6
1.6 5.6
2.0 1.5
2.9 3.2
6.2 4.6
6.8 9.0
6.9 5.9
7.6 8.5
8.1 4.3
7.9 6.4
6.9 13.0
16.0 16.6
17.5 13.6
19.9 16.9
16.9 11.5
14.4 16.3
12.3 1.8
2.8 5.3
1.9 2.2
4.6 5.9
2.5 3.7
5.4 7.7
2.0 5.1
2.1 6.8
1.0 2.9
4.2 4.0
1.6 2.9
5.2 4.8
1.8 3.0
1.5 1.9
0.6 0.8
2.4 1.4
0.7 0.8
4.5 2.1
T = temperature, t = time, C = concentration
Bulletin of Chemical Reaction Engineering Catalysis, 10 1, 2015, 57
Copyright © 2015, BCREC, ISSN 1978-2993 cracking reaction temperature at 450
o
C for 90 minutes using a catalyst of 0.5 wt..
Coke formation rate is a measure of the suc- cess of the process of production of liquid fuels.
In Figure 3 as well, it can be shown that the coke produced were very low 0.8 wt. al-
though with increasing catalyst concentration. At 450
o
C and with a fairly low concentration of catalyst of 0.5, coke produced reached its low-
est point with a reaction time of 90 minutes. In these conditions gasoline fuel fractions also was
produced at highest level. Thus, these condi- tions provide a high selectivity towards gaso-
line fraction. Effect of usage of catalyst is shown in Figure 6. Gasoline, a dominant
product of liquid fuel has the same behavior with liquid fuels. The concentration of gasoline
clearly higher for reaction time of 90 minutes than 60 minutes happened at reaction tem-
perature of 450
o
C. The use of catalysts 0.5 wt. shows an increase of yield product of 20-
25 than reaction without catalyst. However, the use of 1.0 wt. catalyst on catalytic crack-
ing for 90 minutes shows a decrease yield after peak of yield on 0.5 wt. catalyst usage.
Some fraction of liquid fuel produced, gaso- line fraction always provided the greatest con-
version compared to other fractions such as die- sel, and kerosene products. In general it can
notice that the concentration of gasoline pro- duced as selective product is a function of tem-
perature, catalyst concentration, and reaction time. However, for a reaction time of 90
minutes and a catalyst concentration of 0.5 wt., the trend of gasoline fraction increased
with increasing temperature and time is the case. It was due to the limited amount of cata-
lyst in the reaction system was not supported with adequate contact time between reactants.
3.5. Kinetics Parameter Estimation
